The invention relates to quick-opening, remotely actuated valves and more particularly to electrically initiated flooding valves which are normally held in closed position by a pyrotechnic bolt and opened by gas pressure generated when the bolt fuses and separates.
High speed valves have found many commercial and military applications where remote and instantaneous actuation of these normally closed valves is required. One use of particular concern has involved the flooding of underwater apparatus, such as mines, where the valve is initially closed to seal the opening provided for flooding the apparatus, and at the appropriate time, opened to effect flooding thereof.
Previous systems of accomplishing high speed valve action which have used detonating chemicals for actuation are typified by U.S. Pat. No. 3,530,759 to Francis, U.S. Pat. No. 3,254,555 to Joneikis, and U.S. Pat. No. 3,200,706 to Kinard. However, the detonating chemicals in Francis represent a safety hazard, particularly during storage, and in Joneikis and Kinard, the generation of actuation noise during detonation of an explosive charge is pronounced and unavoidable. Some systems, e.g., U.S. Pat. No. 3,728,934 to Palmer, have attempted to provide an irreversibly severable linkage which is fused or destroyed by a thermite mixture thus eliminating the use of detonating chemicals. Unfortunately, Palmer does not confine the products of combustion nor does he produce a motive fluid useful for doing work.
Other known systems of accomplishing high speed valve action include (1) the use of exposed explosive charges, such as shown in U.S. Pat. No. 3,983,892 to Hardesty, U.S. Pat. No. 3,780,752 to Noddin et al, U.S. Pat. No. 3,469,733 to Montgomery et al and U.S. Pat. No. 3,109,553 to Fike et al, which create noise, heat and flame hazards when initiated, and (2) the use of a confined explosive to propel a piston or pin against a frangible shear element which are shown in U.S. Pat. No. 3,494,370 to Wahl et al, U.S. Pat. No. 3,474,809 to Gordon, U.S. Pat. No. 3,202,162 to Eckardt et al, U.S. Pat. No. 3,141,470 to LaFontaine and U.S. Pat. No. 3,093,151 to Merkowitz. While these systems provide high speed valve actuation, they do not have, in general, the capacity to minimize noise and shock. The failure to provide such an optimally silent actuating mechanism may prove extremely deleterious where the apparatus is to be subjected to detection countermeasures.
Where used with submersible apparatus, the high speed valves are usually employed as flooding mechanisms. However, those currently available have several recurring problems which are particularly troublesome. For example, those valves which provide large openings often use electrically initiated, separable, explosively actuated bolts which hold the valves closed. These bolts are undesirable since they produce loose or flying parts, generate products of combustion which contaminate the system or the atmosphere, and generally are either difficult to reload, or are simply "single-shot" devices. Other types of valves, which are quieter and non-explosive, have housings with passageways or large portions projecting below the intake port in which the valve is seated, thereby trapping air and making complete flooding of the apparatus impossible. This results undesirably in impeded water influx as well as attenuation of incoming acoustic and pressure signals. Yet another type of valve makes no provision for maintaining a smooth external contour, a feature which is highly desirable for minimizing hydrodynamic drag, especially at the forward end of propelled underwater devices.